Silver and platinum-catalysed addition of O–H and N–H bonds to allenes

Transition-metal catalysed nucleophile addition to allenes is a very powerful tool for the synthesis of functionalised molecules containing heteroatoms, heterocycles in the intramolecular version, or allyl derivatives in the intermolecular version. The reaction has been explored with a wide variety of metals, silver being one of the most effective. Although platinum has somehow been less explored, different reactivities have been observed with this metal, showing the great potential and versatility of this methodology. This review will highlight the reactions with these two metals, silver and platinum, when oxygen or nitrogen nucleophiles are employed. Although most of the examples describe the intramolecular version, some intermolecular reactions with platinum have been described, and will also be covered

Exits from unemployment: recall or new job

This paper studies transitions out of unemployment in Spain distinguishing between recall to the same employer and reemployment in a new job. We use a large sample of newly unemployed workers obtained from Social Security records for Spain. These data contain information about each individual's employer identy before and after the unemployment spell. A discrete-time duration model with competing risks of exits serves us to investigate the factors that influence the probabilities of leaving unemployment to return to the same employer or to find a new job with a different employer. We find that the route to exit unemployment is determinant to understand the influence of individual an job characteristics on the hazard rate, as well as the latter dependence on unemployment duration. The recall hazard rate exhibits positive duration dependence during the first months and negative duration dependence thereafter (it is larger for females), while the new-job hazard presents positive duration dependence (it is larger for males).

Reducing perseverations in a Spanish speaker with aphasia: A case study

A single-subject design was utilized to examine treatment outcomes following implementation of an activation theory based treatment for perseveration. Treatment involved the use of systematic reduction of inter-stimulus interval paired with semantic feature analysis. The treatment resulted on a decrease in perseveration and increase in accuracy on trained lists. A decrease in preservations was evident from pre- to post- treatment performance on the BNT

Downsizing implementation and financial performance

In the present study we explore the relationship between downsizing decisions and corporate financial performance after top management has decided to downsize. Our focus is on the financial consequences arising from the amount of downsizing and the use of disengagement incentives. For this purpose, we use a sample of downsizing announcements in the Spanish press from 1995 up to 2001. Although the results show that the amount of downsizing is not significantly related to post-downsizing profitability, the evidence provided supports the finding that the use of disengagement incentives (which motivate workers to leave the organization) is negatively related to firm performance. Our analysis helps to understand the role that strategic downsizing decisions play in explaining observed variance in the performance of downsized firms. Thus, it advances scholarly organizational research by reinforcing the concept that corporate performance is not only contingent on strategies, but also influenced by the means through which these strategies are implemented.Downsizing, Disengagement incentives, Corporate performance, Spanish labour market

Does downsizing improve organizational performance? An analysis of Spanish manufacturing firms

The objective of this study is to examine the effect of downsizing on corporate performance, considering a sample of manufacturing firms drawn from the Spanish Survey of Business Strategies during the 1993- 2005 period. No significant differences in post-downsizing performance arise between companies which downsize and those that do not. Likewise, we find that substantial workforce reductions through collective dismissals do not either lead to improved performance levels. Downsizing, therefore, may not be a way for managers to increase performance, particularly in a context like the Spanish one, where the labour market is characterized by a high protection of employees’ rights and substantial contract termination costs.Downsizing, Corporate performance, Spanish labour market

Distributed Consensus to Enable Merging and Spacing of UAS in an Urban Environment

This paper presents a novel approach to enable multiple Unmanned Aerial Systems approaching a common intersection to independently schedule their arrival time while maintaining a safe separation. Aircraft merging at a common intersection are grouped into a network and each aircraft broadcasts its arrival time interval to the network. A distributed consensus algorithm elects a leader among the aircraft approaching the intersection and helps synchronize the information received by each aircraft. The consensus algorithm ensures that each aircraft computes a schedule with the same input information. The elected leader also dictates when a schedule must be computed, which may be triggered when a new aircraft joins the network. Preliminary results illustrating the collaborative behavior of the vehicles are presented

WHAT IS THE LENGTH OF A SNAKE?

The way that herpetologists have traditionally measuredlive snakes is by stretching them on a ruler andrecording the total length (TL). However, due to the thinconstitution of the snake, the large number of intervertebraljoints, and slim muscular mass of most snakes,it is easier to stretch a snake than it is to stretch anyother vertebrate. The result of this is that the length ofa snake recorded is infl uenced by how much the animalis stretched. Stretching it as much as possible is perhapsa precise way to measure the length of the specimenbut it might not correspond to the actual length ofa live animal. Furthermore, it may seriously injure a livesnake. Another method involves placing the snake in aclear plexiglass box and pressing it with a soft materialsuch as rubber foam against a clear surface. Measuringthe length of the snake may be done by outlining itsbody with a string (Fitch 1987; Frye 1991). However, thismethod is restricted to small animals that can be placedin a box, and in addition, no indications of accuracy of thetechnique are given. Measuring the snakes with a fl exibletape has also been reported (Blouin-Demers 2003)but when dealing with a large animals the way the tapeis positioned can produce great variance on the fi nal outcome.In this contribution we revise alternative ways tomeasuring a snake and propose a method that offers repeatableresults. We further analyze the precision of thismethod by using a sample of measurements taken fromwild populations of green anacondas (Eunectes murinus)with a large range of sizes

Optical Two-Dimensional Coherent Spectroscopy of Many-body Dynamics in Quantum Materials

Since the rise of the concept of quantum materials (QM), these materials described as many-body quantum systems (interacting atoms, molecules, or electrons) have been suitable for many optoelectronic and quantum applications. Additionally, there has been significant interest in the research of QM to understand the underlying physics behind their extraordinary optical properties. Examples of QM are ultracold atoms, layered 2D semiconductors, supramolecular materials, and more. In 2012, a high energy conversion efficiency of over 10% was reported for the first time for metal-halide perovskite (MHP) solar cells, opening a new era for photovoltaics research. The reported efficiencies have been improved to 22.7% over the years. Additionally, these exceptional semiconductor MHP materials are also promising candidates for the new generation of optoelectronics. This dissertation focuses on studying many-body interactions and their dynamics of MHP methylammonium lead iodide (MAPI) CH3NH3PbI3 thin film materials at room temperature. In this work, I utilized cutting-edge optical spectroscopies techniques to study ultrafast dynamics of photoexcited electron-holes pairs in MAPI perovskites films. I first performed steady-state spectroscopic measurements to characterize the sample, then implemented optical 2D coherent spectroscopy in the nonlinear geometry to probe the ultrafast dynamics. My experiment revealed many-body couplings and ultrafast dynamics of free-carrier and exciton resonances that coexist for a few hundreds of femtoseconds. According to the results of the 2DCS experiments, the coupling and dynamics of the featured resonances studies were divided into short time (few femtoseconds) and longtime dynamics. The data revealed the charge-carrier relaxation dynamics after the excitation of the sample in terms of thermalization, cooling, exciton dissociation, and many-body effects. Furthermore, those dynamics showed dependence on the excitation control variables, such as wavelength excitation and photoexcited carrier density generated

A comparison of treatment outcomes following whole-task and part-task methods for training scripts

functional purposes for individuals with nonfluent aphasia. The goal of script training is to generate fluent speech in a limited context by restoring portions of automatic, natural language production into the speech of individuals with aphasia. A whole task approach (e.g. facilitating production of a set of related sentences as a unit) has resulted in fluent production of scripts that generalizes to functional contexts (Youmans, Holland, Munoz, & Bourgeois, 2005). Further research is necessary to determine how script training compares to traditional linguistic-based therapy. Though script training is intended to improve functional communication, some participants have demonstrated generalized improvement in language, as evidence by increase in verbal output from pre-test to post-test discourse samples (Powers and Munoz, 2004). The purpose of this study is to explore how treatment outcomes from a whole-task script training method compare with outcomes from part-task (linguistic-based) method. Specifically, we examined response to treatment, generalization to functional contexts, and general increase in language output. Participant Description. A multiple baseline across behaviors single-subject design was used to examine the effects of the treatments. DP was a 46 year-old man 2 years post onset of a left CVA. He passed a hearing screening, a simple screening for visual acuity, an oral mechanism screening, and the Mini-Mental State Exam. Pre Treatment Assessment. DP exhibited Broca’s aphasia as demonstrated by performance on the Western Aphasia Battery (AQ=54). Additionally, narrative and conversational samples were obtained using the Cookie Theft picture from the Boston Diagnostic Aphasia Examination (BDAE) and the Picnic picture from the Western Aphasia Battery. Conversation samples were obtained by asking DP to provide the following information: “Tell me about your most frightening experience,” “Tell me about your stroke,” or “Tell me what you usually do on Saturdays.” Script Training. Three scripts were developed as a collaborative effort between the clinicians and DP. We identified three scripts that were unique, relevant, and functional. Scripts consisted of 4-5 syntactically complete sentences. One script was used in whole-task training (Script 1), one in part-task training (Script 2), and one served as an untrained probe (Script 3). DP attended 50 minute sessions two times per week. Additionally, 15 minutes a day he complete at home practice consistent with each treatment method. Scripts were probed at the start of each treatment session and audiotaped and transcribed for analysis using the Systematic Assessment of Language Transcription (SALT). Script production was analyzed for the following dependant variables: total number of main body words, number of maze words, and percentage of mazes and frequency counts for designated word codes (for example, Correct Script Word [CSW]). Whole-Task Training. Script 1 was trained using the whole-task approach. Repeated drill and a self-cuing hierarchy was used promote fluent production of the target script. Cueing sheets (see Figure 1 for an example) for each sentence were placed in separate pages of a talking photo album. Additionally, the use of a talking photo album allowed for the use of an audio cue (the clinician producing each sentence). The first script sentence was practiced; additional sentences were added in a forward chaining procedure when 100% accuracy had been reached in a single session following three consecutive attempts. Auditory and visual cues to support repetitive drill were controlled by the participants (i.e. the patient was taught to initially use the most facilitative cue [audio] then work his way up and down the hierarchy depending on effort) The criterion for attainment of script was 100% script accuracy during an independent probe. DP’s baseline performance on Script 1 was established over three sessions (Figure 3). He reached the 100% accuracy criterion following 8 treatment sessions. Accuracy of script production, as measured by percent correct script words (script words produced/total script words) was generally maintained at or above 80% after completion of training. The WAB was re-administered following Script 1 Training and DP demonstrated an increase in AQ (65, + 11 points). Additional data will be reported regarding pre- and post- test performance on discourse tasks, as well as additional measures obtained on script performance (such as error type). Interview with the participant indicated that he was using the script in a variety of functional contexts (for example, at church and on the phone). Part-Task Training. The syntactic structures of Script 2 were trained using a modified version of the Sentence Production Program for Aphasia (Helm-Estabrooks & Nicholas, 2000). The SPPA is a treatment program with hierarchically organized sentence types (beginning with easier sentences), 15 sentences per level. The syntactic structure is first trained with a model, then elicited with a cue (see Figure 2 as an example). The script sentences were integrated to SPPA sentences with a comparable syntactic structure. The criterion for attainment of script was 100% script accuracy during an independent probe. DP’s baseline performance on Script 2 was established over eleven sessions (Figure 4). Treatment was initiated at SPPA sentence type 4 (Wh- questions) and included the script sentences (also Wh- questions, see example Figure 2). DP exhibited frustration at Level 4 and could not score above a 2 (out of 15); therefore, treatment at SPAA Sentence Type 1 was initiated. DP progressed through the SPPA levels (using criteria provided in the treatment manual) until level 4 was reached, at which point the script sentences were once again integrated with the comparable SPPA sentences. DP met criteria for completion of SPAA level 4 which included correct production of Script sentences. However, correct production within the context of the SPPA cuing did not transfer to independent probes (Figure 4). DP did not reach the 100% criterion. Accuracy of script production did not exceed 11%. The WAB was re-administered following Script 2 training and DP demonstrated a minimal change in AQ (63, -2 points). Additional data will be reported regarding pre- and post- test performance on discourse tasks, as well as additional measures obtained on script performance (such as error type). Currently, we are in the process of completing the protocol with a second participant and expect to have the data to present. References Helm-Estabrooks, N., & Nicholas, M. (2000). Sentence Production Program for Aphasia. Austin, TX: Pro-ed. Youmans, G., Holland, A., Munoz, M. L., & Bourgeois, M. S. (2005). Script training and automaticity in two individuals with aphasia. Aphasiology, 19(3-5), 435-450. Powers, H. and Muñoz, M.L. (November, 2004) Treatment outcomes following script training for Broca’s aphasia. Poster session presented at the annual convention of the American Speech Language and Hearing Association